Abstract
The physiological and ecological characteristics which crops show in the course of their growth, are responses of potential energies in crop body to environmental factors. Potential energies which seeds of crops hold, may response in a similar way when seeds are placed under similar conditions. From this point of view, the author tried to determine catalase activities in seeds of various kinds of rice plants at both temperatures, 10° and 30°C (36 varieties of lowland and upland rices grown in Japan, China and tropics). And the thermosensitiveness of the ferment expressed by the ratio of the differences between activities at both temperatures to that at low temperature, was calculated in each varieties. The results were as follows: 1. The activity at l0°C was almost higher in earlier varieties than in those of later heading. The correlation value between the activity and the duration of the growth was shown in r=0.539. 2. The activity at 30°C was almost higher in later varieties than in those of earlier heading. The same value as shown above was r=-0.414. 3. The thermosensitiveness of the ferment, was higher in earlier varieties than in later ones. The correlation value between the sensitiveness and the duration of the growth was shown in r=-0.693. The earlier varieties of rice plants are used to be grown in relatively cooler regions and the later ones in warmer regions. The earlier varieties head remarkably earlier when they are grown in warmer regions. Potential energy, namely the ferment in seeds of rice varieties used, showed such corresponding responses to temperatures as plants do in their growth.
